I've read that the BASIC of the Timex Sinclair 2068 is a superset of the BASIC of the Sinclair ZX Spectrum with a few extra keywords.
The extra keywords are:
DELETE delete BASIC program lines,
FREE reports free RAM,
ON ERR for error handling,
RESET which is used in combination with
SOUND for using the AY-3-8192 chip, and
STICK for getting the joysticks' states.
In RAM and in a saved BASIC program, the Spectrum like many BASICs uses a tokenized format where each BASIC keyword has a 1-byte token. Here's one website documenting the tokens. There are probably several others around.
Now I know that the TS 2068 has extra keywords, but I can't find any information on how they are encoded as tokens.
Now Sinclair BASIC is odd in that all keywords are also "characters" in the character set, but note that the tokens do not match the "ASCII" codes. As far as I can see, only two of the 2068's extra keywords are given character codes:
STICK is character
0x7c where the Speccy has
FREE is at
0x7e where the Speccy has
~. This all probably has no bearing at all on the tokenization, so don't be confused.